For the magazine's "Ageless Style" edition, the model wears a white Acne mohair jumper and her hair is a perfectly balanced combination of disheveled and done - the image is photographer David Bailey at his finest. Summing it up in word? Beautiful is pretty spot on.

But here's the niggle - the question that just refuses to go away: how does Turlington Burns look almost as young on this cover as she did on her last one for the publication, shot way back in 1996?

There's really only two possibilities - airbrushing or just the best genes you can possibly imagine. Or magic! Perhaps this is actual magic!

Equally, it could be her lifestyle. At the height of her fame, the 45-year-old quit the catwalk to go to university and take time away from the fashion industry.

Speaking to Interview magazine in 2013, she said: "I never thought I would model for more than a few years. Each year I would say 'one more year' and that got old.

"So, after one particularly gruelling season at the couture shows in Paris in the summer of '94, I decided that was it. I came home and applied to NYU and started classes that fall."

Since then, Turlington Burns has designed two clothing lines for Puma, become an authority in all things yoga and is an owner of skincare range Sundari.

In addition, she founded Every Mother Counts - a campaign to reduce the number of women needlessly dying during pregnancy and through childbirth all over the world.

Also, speaking about deliveries via Cesarean section in a recent interview with Huffington Post Live, Turlington-Burns spoke out against the procedure and the "overmedicalisation" of giving birth.

"It's the norm in this country to have a Cesarean section, and that is dangerous for both moms and children," she said. "Women are more likely to have a ruptured uterus if they've had multiple C-sections because there's more scar tissue."

As well as her humanitarian work, Turlington Burns is also the face of Calvin Klein.